Integrated data conversion and viewing station for medical images

ABSTRACT

A method, in a picture archiving and communication system (PACS), for processing raw image data at a PACS display workstation includes the step of retrieving from a PACS database raw image data delivered from an imaging modality. The method also includes selecting from a PACS database a first preprocessing function for the raw image data delivered from the imaging modality. The method then processes the raw image data at the PACS display workstation by applying the first preprocessing function to the raw image data to create resultant image data, which may then be stored in the PACS database for future retrieval. A PACS display workstation includes a processing circuit, a PACS network interface coupled to the processing circuit, and a software memory coupled to the processing circuit. The software memory stores instructions for retrieving from a PACS database raw image data delivered from an imaging modality, selecting from a PACS database a first preprocessing function for the raw image data delivered from the imaging modality, and processing said raw image data at the PACS display workstation by applying the first preprocessing function to the raw image data.

BACKGROUND OF THE INVENTION

This invention relates to picture archiving and communications systems,and more particularly relates to image viewing and manipulationworkstations for use in such systems.

Picture archiving and communication systems (PACS) connect to medicaldiagnostic imaging devices and employ an acquisition gateway (betweenthe acquisition device and the PACS), storage and archiving units,display workstations, databases, and sophisticated data processors.These components are integrated together by a communication network anddata management system. A PACS has, in general, the overall goals ofstreamlining health-care operations, facilitating distributed remoteexamination and diagnosis, and improving patient care.

PACS have only recently been introduced to the medical community. Areflection of their recent appearance may be seen in limitationsinherent with many of the components used to build a PACS. As anexample, the acquisition gateway that acquires raw image data from animaging modality initially modifies the raw image data usingpreprocessing functions (as one example, FUJI preprocessing functions).The preprocessing functions modify the raw image data for contrast andfrequency enhancements, for example, and the acquisition gateway furtherconverts the resultant image data into a PACS compliant format, forexample DICOM format. The preprocessing functions initially applied bythe acquisition gateway bar the reapplication of the preprocessingfunctions at the display workstation. Thus, the display workstationscoupled to the PACS are unable to perform sophisticated imagemodifications possible only by applying the preprocessing functions tothe raw image data.

In other words, the display workstations used in PACS are adapted onlyfor viewing fully preprocessed image data and performing limited imagemodification (e.g., contrast enhancement, edge detection, and croppingonly on the image data in PACS compliant format). An initial imagepreprocessing decision is thereby imposed upon all subsequent viewers ofthe image, including, for example, doctors who will use the image todiagnose a patient. While a preprocessed image may, in fact, be adequatefor a particular examination, such preprocessing eliminates thepossibility for custom manipulation of the raw image data as anadditional aid in diagnosis.

This invention addresses this problem and provides a solution.

BRIEF SUMMARY OF THE INVENTION

A preferred embodiment of the present invention includes a method, in apicture archiving and communication system (PACS), for processing rawimage data at a PACS display workstation. The method includes the stepof retrieving from a PACS database, using a PACS workstation, raw imagedata delivered from an imaging modality. The method also includesselecting from a PACS database, using the PACS workstation, a firstpreprocessing function for the raw image data delivered from the imagingmodality. The preprocessing function is characterized in that [ ]. Themethod then processes the raw image data at the PACS display workstationby applying the first preprocessing function to the raw image data tocreate resultant image data, which may then be stored in the PACSdatabase for future retrieval.

A preferred embodiment of the present invention also includes, in apicture archiving and communication system (PACS), a PACS displayworkstation. The workstation includes a processing circuit, a PACSnetwork interface coupled to the processing circuit, and a softwarememory coupled to the processing circuit. The software memory storesinstructions for execution by the processing circuit for retrieving froma PACS database raw image data delivered from an imaging modality,selecting from a PACS database a first preprocessing function for theraw image data delivered from the imaging modality, and processing saidraw image data at the PACS display workstation by applying the firstpreprocessing function to the raw image data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a high level block diagram of a PACS system.

FIG. 2 illustrates a PACS display workstation for processing raw imagedata.

FIG. 3 illustrates a flow diagram of a method for processing raw imagedata delivered from an imaging modality.

FIG. 4 shows a flow diagram of a method for default processing ofoperator preferences.

FIG. 5 depicts a flow diagram of a technique for partially preprocessingraw image data delivered from an imaging modality.

FIG. 6 shows a block diagram of an acquisition workstation.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to FIG. 1, that figure shows a medical data network 100including an imaging modality 102, an acquisition workstation 104, and aPACS network 106. The PACS network 106 includes a PACS image database108, a raw image data and preprocessing function database 110(“preprocessing database 110”), and display workstations 112, 114, 116.A set of operator preferences 118 is stored in the preprocessingdatabase 110.

The imaging modality 102 is generally a medical diagnostic imagingdevice. For example, the imaging modality 102 may be an X-ray imager,ultrasound scanner, magnetic resonance imager, or the like. The imagingmodality 102 generates raw image data as a result of an examination. Theimaging modality 102 is connected to the acquisition workstation 104using, for example, a network connection or dedicated interface port.

The acquisition workstation 104 acts as a gateway between the imagingmodality 102 and the PACS network 106. To that end, the acquisitionworkstation 104 accepts raw image data from the imaging modality 102. Inturn, the acquisition workstation 104 optionally performs preprocessingon the raw image data (as described in more detail below) in preparationfor delivering image data to the PACS network 106 for storage in thePACS image database 108 or preprocessing database 110. In operation, theacquisition workstation 104 may convert the raw image data into a DICOMstandard format, attach a DICOM header, and the like.

The PACS image database 108 and the preprocessing database 110 areillustrated in FIG. 1 for convenience as separate databases. However,they may be a single database, separate databases on an single computer,or separate databases distributed among different computers. In general,the PACS image database 108 stores fully preprocessed images (i.e.,those images for which no additional preprocessing functions will beapplied). On the other hand, the preprocessing database 110 storespartially preprocessed image data (“raw image data”) (i.e., that imagedata that has not yet been completely preprocessed).

The display workstations 112–116 are coupled to the PACS image database108 and the preprocessing database 110. Thus, the display workstations112–116 may retrieve images from the PACS image database 108 forimmediate modification and display, or the display workstations 112–116may retrieve raw image data from the preprocessing database 110. Whenthe display workstations 112–116 retrieve raw image data, however, theraw image data is further modified by preprocessing functions to formresultant image data. The resultant image data may then represent afully preprocessed image, or may require additional preprocessing beforebeing stored as a fully preprocessed image.

The preprocessing functions are characterized in that they are modalityspecific enhancements (e.g., contrast or frequency compensationfunctions specific to a particular X-ray imaging device, for example)applied at the beginning of the imaging and display chain. Thepreprocessing functions differ from the processing functions applied tofully preprocessed images in that the processing functions are notmodality specific and are instead applied the end of the imaging anddisplay chain.

Turning now to FIG. 2, that figure illustrates a PACS displayworkstation 200 suitable for use in the PACS network 106. The displayworkstation 200 includes a general purpose processing circuit 202, aPACS network interface 204, a software memory 206, and an image displaymonitor 208. The PACS network interface 204 is generally implemented asa network card connecting to a TCP/IP based network, but may also beimplemented as a parallel port interface, or the like. In particular,the software memory 206 is a raw image and preprocessing functionsoftware memory.

Thus, the software memory 206 includes, for execution by the processingcircuit 202, instructions for retrieving, from a PACS database, rawimage data delivered from an imaging modality. The instructions alsoallow the operator at the PACS workstation 200 to select a preprocessingfunction for the raw image data. Once the raw image data and thepreprocessing function are determined, the instructions in the softwarememory 206 allow the processing circuit 202 to apply the preprocessingfunction to the raw image data to create resultant image data.

As an example, the raw image data may be frequency preprocessed rawimage data or contrast preprocessed raw image data. In other words, theacquisition workstation 104 may have already performed a limitedpreprocessing of the raw image data and stored the results in thepreprocessing database 110. In a preferred embodiment, the acquisitionworkstation 104 applies a subset of predetermined preprocessingfunctions (e.g., frequency preprocessing functions) to the raw imagedata, allowing the remaining preprocessing functions (e.g., contrastpreprocessing functions) to be applied by the PACS workstations 112–116that thereby generate a fully preprocessed image. Raw image datatherefore may be regarded as image data initially acquired from animaging modality and that has not been fully preprocessed according topredetermined set of preprocessing functions (e.g., the FUJIpreprocessing functions).

In selecting the preprocessing function, the PACS workstation 200 allowthe operator to choose one or more remaining preprocessing functions(e.g., frequency or contrast preprocessing functions) for application tothe raw image data to generate resultant image data. The resultant imagedata may be stored in the preprocessing database 110 for futurepreprocessing, or, if all preprocessing has been accomplished, theresultant image data may be stored in the PACS image database 108 forfuture processing and display.

In other words, once the resultant image data has been fullypreprocessed, conventional image processing algorithms may be applied.The processed resultant image data may then be displayed on the imagedisplay monitor 208.

One specific example of preprocessing functions are the industrystandard FUJI Computed Radiography (CR) modality preprocessingfunctions. The FUJI preprocessing functions include contrastpreprocessing functions and frequency preprocessing functions. Thecontrast preprocessing functions are characterized by the followingparameters: GT (contrast type), GA (rotation amount of GT curve), GC(rotation center for GT), and GS (density shift, the amount of shiftingapplied to GT). The frequency preprocessing functions are characterizedby the following parameters: RN (frequency rank), RE (frequencyenhancement), and RT (frequency type). Each preprocessing function mayrepresent a linear or non-linear function, function modification, orfunction parameter. The preprocessing functions may be applied to rawimage data any time prior to the image processing and display.

The preprocessing functions may be selected based, for example, on ananatomical region to which the raw image data corresponds. In otherwords, the preprocessing functions selected may vary depending onwhether the raw image data represents, as examples, the head, neck,chest, abdomen, breast, lungs, pelvis, or shoulders. The preprocessingfunctions may vary for each anatomical region due to the differences intissue, bone, and blood vessel density and prevalence.

The display workstations 112–116 preferably allow their operator to saveoperator preferences in the PACS system 106 for future retrieval andsubsequent application. As an example, the display workstations 112–116may identify an operator by login name or by querying the operator foran identification code. As the operator works with the preprocessingfunctions, the operator may develop a preference for application ofspecific preprocessing functions. The display workstations 112–116 savethe operator preferences 118 in, for example, in the preprocessingdatabase 110. When the operator logs in at a later time, the displayworkstations 112–116 query the database for the operator preferences 118(e.g., based on login name or operator ID) and retrieve any preferencesfound.

The display workstations 112–116 may then apply the retrieved operatorpreferences 118 by default to any raw image data currently retrieved bythe display workstations 112–116. The operator preferences 118 mayinclude additional information other than the preferred preprocessingfunctions, including screen resolution, image layout and position, andcolor information. Furthermore, the operator preferences 118 mayadditional be stored based on anatomical areas of interest. For example,the operator preferences 118 may include the default preprocessingfunctions to be applied for neck images, and the default preprocessingfunctions to be applied for chest images.

Turning now to FIG. 3, that figure illustrates a flow diagram 300 of amethod for processing raw image data, and the software steps executed bythe processing circuit 202. At step 302, the processing circuit 202(e.g., manually under operator control or automatically in accordancewith an automated processing script) retrieves raw image data from thepreprocessing database 110. Subsequently, the processing circuit 202selects (manually or automatically) a preprocessing function from thepreprocessing database 110 (step 304). During step 306, the processingcircuit 202 applies the preprocessing function to the raw image data. Asexamples, the preprocessing function may include frequency controlpreprocessing (step 308) or contrast control preprocessing (step 310).

After the preprocessing functions are finished, the processing circuit202 may then apply additional image processing techniques (e.g., edgedetection, edge enhancement, noise reduction, image cropping, contrastenhancement, and the like) to the fully processed resultant image data(step 312). At step 314, the processed resultant image data isdisplayed.

Before an operator at a display workstation 112–116 begins work, thedisplay workstations 112–116 may retrieve and apply default operatorpreferences. Turning now to FIG. 4, that figure shows a flow diagram 400of the steps that a display workstation 112–116 executes to apply thedefault operator preferences. At step 401, the display workstation112–116 identifies the operator using, for example, a login name andpassword. Next, at step 402, the display workstation 112–116 queries adatabase for operator preferences 118. If operator preferences 118 donot exist, then processing continues at step 408. If operatorpreferences 118 do exist, then the display workstation 112–116 retrievesthe operator preferences 118 (step 404). Subsequently, at step 406, thedisplay workstation 112–116 applies the operator preferences 118 (e.g.,screen resolution, image layout, colors, and the like), and inparticular applies the preprocessing function preferences as defaults tothe current raw image data that the operator is working with.

Continuing at step 408, the display workstation 112–116 allows theoperator to continue to preprocess the raw image data and to processfully preprocessed image data. The operator may also adjust the operatorpreferences, such as screen size, image orientation, preprocessingfunction preference, and the like. In other words, the displayworkstation 112–116 allows the operator to establish new operatorpreferences (step 408). When the operator is finished using the displayworkstation 112–116, the display workstation 112–116 saves the (possiblynew or revised) operator preferences in a database, if the operator soinstructs the display workstation 112–116 (step 410).

As noted above, the acquisition workstation 104 may apply a subset ofpredetermined preprocessing functions (e.g., frequency preprocessingfunctions) to the raw image data, allowing the remaining preprocessingfunctions (e.g., contrast preprocessing functions) to be applied by thePACS workstations 112–116 that thereby generate a fully preprocessedimage. Turning now to FIG. 5, that figure illustrates a flow diagram 500of the processing that occurs at an acquisition workstation 104. Aninitial step (step 502) is taken to store predetermined preprocessingfunctions at the acquisition workstation 104 (e.g., by storingfunctions, lookup tables, piecewise linear curve approximations, curveparameter values, and the like).

Next, at step 504, the acquisition workstation 104 receives raw imagedata from an imaging modality. Subsequently, the acquisition workstation104 preferably applies at least one, but less than all preprocessingfunctions to the raw image data (step 506) to form partiallypreprocessed raw image data. The display workstations 112–116 maythereby complete the image preprocessing on the partially preprocessedraw image data using the flexible preprocessing functions. When theacquisition workstation 104 is finished, it transmits the partiallypreprocessed raw image data to the PACS network 106 for storage in thepreprocessing database 110 (step 508).

Turning now to FIG. 6, that figure illustrates one embodiment of anacquisition workstation 600 suitable for use with the PACS network 106.The acquisition workstation 600 includes a processing circuit 602, aPACS network interface 604, and an imaging modality interface 606. Theacquisition workstation 600 also includes a software memory 608, and animage display monitor 610. The PACS network interface 604 and imagingmodality interface 606 are generally implemented as network cardsconnecting to a TCP/IP based network, but may also be implemented asparallel port interfaces, proprietary hardwired or wireless interfaces,or the like.

The software memory 608, in particular, is a raw image datapreprocessing software memory. Thus, the software memory 608 includes,for execution by the processing circuit 602, instructions for performingthe functions described above in the flowchart of FIG. 5. In otherwords, the acquisition workstation 600 receives raw image data over theimaging modality interface 606, partially preprocesses the raw imagedata to form partially preprocessed raw image data, and transmits thepartially preprocessed raw image data through the PACS network interface604 to the PACS network 106.

The raw image data preprocessing method and PACS workstation of thepreferred embodiment thus provide much more extensive and detailed imagemodification possibilities to the display workstation operator. Thepresent method and workstation thus remove the initial imagepreprocessing decisions imposed by prior systems upon all subsequentviewers of the image. Thus, doctors and technicians may perform custommanipulation of the raw image data as an additional aid in diagnosis.

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the invention without departing from its scope.Therefore, it is intended that the invention not be limited to theparticular embodiment disclosed, but that the invention will include allembodiments falling within the scope of the appended claims.

1. In a picture archiving and communication system (PACS), a method ofprocessing image data at a PACS display workstation, the methodcomprising: retrieving from a PACS database, using a PACS displayworkstation, partially preprocessed raw image data, said partiallypreprocessed raw image data having been partially preprocessed accordingto a predetermined subset of preprocessing functions obtained from a setof preprocessing functions comprising at least contrast and frequencypreprocessing functions, said predetermined subset of preprocessingfunctions applied to modality raw image data at an acquisitionworkstation, said modality raw image data delivered from an imagingmodality; selecting from a PACS database, using the PACS displayworkstation, a first preprocessing function for the partiallypreprocessed raw image data, wherein said first preprocessing functionis stored in said PACS database, said first preprocessing functioncomprising the remaining subset of preprocessing functions from the setof preprocessing functions not included in said predetermined subset ofpreprocessing functions; and applying, using the PACS displayworkstation, the first preprocessing function to the partiallypreprocessed raw image data to create resultant image data.
 2. Themethod of claim 1, wherein the step of retrieving partially preprocessedraw image data further comprises retrieving frequency preprocessed rawimage data.
 3. The method of claim 2, wherein the step of selectingfurther comprises selecting a contrast preprocessing function.
 4. Themethod of claim 3, wherein the step of selecting further comprisesselecting a contrast preprocessing function characterized by at leastone of a GT, GA, GC, and GS preprocessing parameter.
 5. The method ofclaim 1, wherein the step of retrieving partially preprocessed raw imagedata further comprises retrieving contrast preprocessed raw image data.6. The method of claim 5, wherein the step of selecting furthercomprises selecting a frequency preprocessing function.
 7. The method ofclaim 6, wherein the step of selecting further comprises selecting afrequency preprocessing function characterized by at least one of a RN,RE, and RT preprocessing parameter.
 8. The method of claim 1, furthercomprising the step of applying an image processing function to theresultant image data to create processed resultant image data.
 9. Themethod of claim 8, further comprising the stop of displaying theprocessed resultant image data.
 10. The method of claim 1, furthercomprising the step of storing the resultant image data in the PACSdatabase for future retrieval.
 11. In a picture archiving andcommunication system (PACS), a PACS display workstation comprising: aprocessing circuit; a PACS network interface coupled to the processingcircuit; and a software memory coupled to the processing circuit, thesoftware memory storing instructions for: retrieving from a PACSdatabase partially preprocessed raw image data, said partiallyPreprocessed raw image data having been partially preprocessed accordingto a predetermined subset of preprocessing functions obtained from a setof preprocessing functions comprising at least contrast and frequencypreprocessing functions, said predetermined subset of preprocessingfunctions applied to modality raw image data at an acquisitionworkstation, said modality raw image data delivered from an imagingmodality; selecting from a PACS database a first preprocessing functionfor the partially preprocessed raw image data, wherein said firstpreprocessing function is stored in said PACS database, said firstpreprocessing function comprising the remaining subset of preprocessingfunctions from the set of preprocessing functions not included in saidpredetermined subset of preprocessing functions; and applying the firstpreprocessing function to the partially preprocessed raw image data tocreate resultant image data.
 12. The PACS display workstation of claim11, wherein the partially preprocessed raw image data corresponds to ananatomical region, and wherein the preprocessing function is selectedbased on the anatomical region.
 13. The PACS display workstation ofclaim 11, wherein the partially processed raw image data is frequencyprocessed raw image data.
 14. The PACS display workstation of claim 13,wherein the preprocessing function is a contrast preprocessing function.15. The PACS display workstation of claim 14, wherein the contrastpreprocessing function characterized by at least one of a GT, GA, GC,and GS preprocessing parameter.
 16. The PACS display workstation ofclaim 11 wherein the partially processed raw image data is contrastpreprocessed raw image data.
 17. The PACS display workstation of claim16, wherein the preprocessing function is a frequency preprocessingfunction.
 18. The PACS display workstation of claim 17, wherein thefrequency preprocessing function characterized by at least one of a RN,RE, and RT preprocessing parameter.
 19. The PACS display workstation ofclaim 11, wherein the software memory further comprises instructions forapplying an image processing function to the resultant image data. 20.The PACS display workstation of claim 1, wherein the software memoryfurther comprises instructions for storing the resultant image data inthe PACS database for future retrieval.
 21. A medical data networkcomprising: an image modality; an image acquisition workstation; a PACSnetwork interfaced to the image acquisition workstation, the PACSnetwork comprising a networked PACS image database, a PACS displayworkstation, and a preprocessing database, and wherein the PACS displayworkstation comprises: a processing circuit; a PACS network interfacecoupled to the processing circuit; and a software memory coupled to theprocessing circuit, the software memory storing instructions for:retrieving from the preprocessing database partially preprocessed rawimage data, said partially preprocessed raw image data having beenpartially preprocessed according to a predetermined subset ofpreprocessing functions obtained from a set of preprocessing functionscomprising at least contrast and frequency preprocessing functions, saidpredetermined subset of preprocessing functions applied to modality rawimage data at the image acquisition workstation, said modality raw imagedata delivered from the imaging modality; selecting from thepreprocessing database a first preprocessing function for the partiallypreprocessed raw image data, wherein said first preprocessing functionis stored in said preprocessing database, said first preprocessingfunction comprising the remaining subset of preprocessing functions fromthe set of preprocessing functions not included in said predeterminedsubset of preprocessing functions; and applying the first preprocessingfunction to the partially preprocessed raw image data to createresultant image data.
 22. The medical data network of claim 21, whereinthe first preprocessing function is a contrast preprocessing functions.23. The medical data network of claim 22, wherein the contrastpreprocessing function characterized by at least one of a GT, GA, GC,and GS preprocessing parameter.
 24. The medical data network of claim21, wherein the first preprocessing function is a frequencypreprocessing function.
 25. The medical data network of claim 24,wherein the frequency preprocessing function characterized by at leastone of a RN, RE, and RT preprocessing parameter.